Joining two pieces of carpet, or closing the junction where carpet meets another covering.

It answers a join rather than an edge.

That is what separates it from edging and transition products.

A carpet join is the weakest line in a floor.

It takes traffic across it and the pieces move independently.

A poor seam frays, peaks or opens within months and does not recover.

Heat-bonded seaming tape, in most modern work.

The tape sits under the join and an iron melts its adhesive.

The two edges bond into a continuous surface.

Nothing is visible above the pile.

That gives the flattest and most durable result.

Binder bars have largely retreated to junctions with other materials.

Where carpet meets a different material, or the join must be demountable.

Doorways where a defined edge is wanted are the common case.

The bar clamps or traps the carpet edge.

It presents a finished profile at the junction.

It also protects the edge from being kicked up.

Where two carpets simply continue, tape gives a better result.

In material, considerably - and it has to be planned at ordering.

A seam across a patterned carpet shows every millimetre of misalignment.

Matching consumes extra length at every join.

Pattern repeat therefore affects how much carpet is needed.

Discovering it at fitting means either a visible seam or a further order.

Plain carpets are far more forgiving and cheaper to seam.

Out of the main traffic path and, where possible, parallel to the light.

A join through a doorway fails sooner than one elsewhere.

Seams under furniture are both protected and hidden.

Light falling across a seam makes it far more visible.

Running the seam towards the window reduces that effect.

Placement is decided when the carpet is planned rather than when it is cut.

Usually edge fraying or the seam opening under traffic.

Carpet edges must be sealed when cut or they fray.

Seam sealer applied to the cut edges prevents it.

Insufficient bond or a cold iron leaves the tape only partly adhered.

Movement in the subfloor also opens seams over time.

Repair is possible early and becomes replacement once the pile edges have worn.

Early ones often can; worn ones generally cannot.

Re-bonding a lifted seam is straightforward while the edges are intact.

Once the pile has worn back from the join, material is missing.

A patch or a new piece is then the only route.

Keeping offcuts from the original fit makes that far easier.

Offcuts also fade differently in storage, so an exact match is not guaranteed.